Safety of maximal cardiopulmonary exercise testing in pediatric patients with pulmonary hypertension

Maximal cardiopulmonary exercise testing (CPX) is valuable to quantifying functional capacity in patients with pulmonary hypertension (PH), but information on CPX in children is limited possibly because of safety concerns. The purpose of this study was to examine the safety of CPX in pediatric patients with PH.

Data were obtained retrospectively from patients referred for CPX at our institution between January 2001 and September 2007. Patients with a 6-min walk distance < 275 m were excluded. Exercise test complications were grouped according to ischemic ECG changes, presence of arrhythmia, and oxygen desaturation at peak exercise and were graded as mild, moderate, or severe.

Twenty-seven patients (4 with idiopathic PH, 23 with secondary PH), 12.5 years of age (range, 6.9 to 18 years), participated in 64 CPX sessions. The mean (+/- SD) peak oxygen uptake was 23.3 +/- 5.4 mL/kg/min, with a mean decrease in arterial oxygen saturation to 85% +/- 15.7% at peak exercise. Mild arrhythmia was detected in 30% of the patients. ST-segment depression was graded as mild (19%) or moderate (1.5%). There were no significant adverse events, such as syncope, chest pain, or dizziness. CPX was stopped for fatigue in 53% of patients, leg fatigue in 23%, dyspnea in 21%, and miscellaneous reasons in 3%.

This study suggests that CPX can be performed safely in pediatric patients with PH, with the exception of patients with severe limitation who were excluded from exercise testing. Although the number of patients in the sample is small, the data imply that the absence of significant patient symptoms and low incidence of arrhythmia or significant ST-segment depression make CPX a safe choice for measuring functional capacity in this patient population.